Loop taker support for sewing machines

ABSTRACT

A support for mounting a loop taker saddle in the bed of a sewing machine in which the saddle is formed along opposite sides with parallel channels which slidably embrace and span ways which are secured in the machine bed. The loop taker saddle may be clamped in selected position in the sewing machine bed by a securing screw which is arranged to deflect one of the ways.

United States Patent Inventor Rudolf Schaier Karlsruhe, Germany Appl.No. 43,062

Filed June 3, 1970 Patented Dec. 21,1971

Assignee The Singer Company New York, N.Y.

LOOP TAKER SUPPORT FOR SEWING MACHINES 2 Claims, 3 Drawing Figs.

U.S.Cl 112/167, 112/184,112/218 R [56] References Cited UNITED STATESPATENTS 2,476,061 7/1949 Parry 112/184 3,310,013 3/1967 Smith 112/184Primary Examiner-H. Hampton Hunter Atrorneys-Marshal1.l. Breen, ChesterA. Williams, Jr. and

Robert E. Smith ABSTRACT: A support for mounting a loop taker saddle inthe bed of a sewing machine in which the saddle is formed along oppositesides with parallel channels which slidably embrace and span ways whichare secured in the machine bed. The loop taker saddle may be clamped inselected position in the sewing machine bed by a securing screw which isarranged to deflect one of the ways.

PATENTEUBEEZ] l9?! 3628;479

SHEET 1 [IF 2 INVENTOR. Rudolf Schafer wrmsss: 2 4%; Q ATTORNEY PATENTEDDEEZI l97| SHEET 2 0F 2 INVENTOR. Rudolf Schufer /Q ATTORNEY WITNESS725w)? H D M LOOP TAKER SUPPORT FOR SEWING MACHINES BACKGROUND OF THEINVENTIQN It is conventional in the sewing machine art, where a looptaker saddle is employed, to support the saddle on the sewing machinebed by fastening which pass through slotted openings in the saddle andattach to the sewing machine bed. Use has also been made of a bed shaftor loop taker drive shaft or of the bushings for such a bed shaft tolocated and support the loop taker saddle. It has been difficult usingthe prior art loop taker saddle-supporting means to provide for anaccurate adjustment of the saddle position because the very tighteningof the fastenings often effected slight shifts of the saddle position.Moreover, with the prior art arrangements it has been difficult toobtain a clamping action which would maintain the loop taker saddle inselected position despite the vibration incident to sewing machineoperation. If the fastening screws or bolts of the prior arrangementswere tightened sufficiently to prevent loosening due to vibration, thefastenings frequently scored or deformed the slotted openings thereforin the saddle thus making it difficult, if not impossible, to obtainfurther slight adjustments at a later time.

SUMMARY OF THE INVENTION It is an object of this invention to provide aloop taker saddle supporting arrangement for sewing machines in whichvery accurate adjustment of saddle position is obtainable and in whichexceedingly positive clamping of the saddle in selected position may beobtained.

It is also an object of this invention to provide a loop takersaddle-supporting arrangement in which clamping of the saddle in oneselected position does not deform or mutilate the clamping means so asto make further slight adjustments difficult.

The objects and advantages of this invention are attained by theprovision of substantially parallel channels in the opposite sides of aloop taker saddle which channels slidably embrace ways secured to thesewing machine bed. Provision is made for deforming one or both of theways causing the loop taker saddle to be clamped in selected positionalong the ways. Sufficiently large area of contact is provided betweenthe ways and the loop taker saddle channels which embrace the ways as toprevent any localized mutilation of these parts which would preventsubsequent slight adjustments in saddle position.

With the above and additional objects and advantages in view as willhereinafter appear, this invention will now be described with referenceto a preferred embodiment illustrated in the accompanying drawings inwhich:

FIG. it represents a vertical cross-sectional view of the bed portion ofa sewing machine having applied thereto the support for mounting a looptaker saddle in accordance with this invention,

FIG. 2 represents an enlarged cross-sectional view taken substantiallyalong line 22 of FIG. 1 showing the loop taker saddle and thesaddle-supporting means of this invention, and

FIG. 3 is a bottom plan view of the sewing machine of FIG. 1.

Referring to FIGS. 1 and 3, a sewing machine is illustrated having a bed11, a standard 12 rising from the bed and sustaining a bracket arm 13which overhangs the bed. The sewing machine is adapted simultaneously toform two separate rows of stitches, and to do this it is provided in thesewing head with a needle bar 14 to which is secured a needle clamp 15which accommodates a pair of laterally spaced needles 16. A throat plate17 carried on the bed to support work fabrics against the thrust of theneedles is formed with apertures 18 through which the needlesreciprocate endwise in the formation of stitches.

Indicated generally at 20 are rotary loop takers for cooperating onewith each of the needles 16 in the formation of stitches. Each looptaker is carried in a saddle indicated generally at 21 which isshiftably supported lengthwise of the bed and may be clamped in selectedposition thereon. When a different spacing between the separate lines ofstitches is required, a different needle clamp 15 is substituted havingthe desired gauge or needle spacing, a different throat plate issubstituted having the appropriately spaced needle apertures, and theloop taker saddles 21 must be shifted into a new spacing of the looptakers for cooperation with the changed needle gauge. As is conventionalin this type of two needle sewing machine, regardless of the needlespacing, the needles will always be arranged equally on opposite sidesof a fixed medial plane. When'needle gauge is changed, therefore, ashift of the loop taker position of the two loop takers will always berequired an equal amount in opposite directions.

The two loop taker saddles may be identical in construction andidentical in means of support, and therefore the same parts will beindicated by like reference characters in the drawings save that theparts of the righthand saddle in the drawings will be denoted by primenumbers.

As best shown in FIG. 2, each of the loop taker saddles 21 comprises aclosed compartment 22 through which a pair of vertical shafts 23 and 24are joumaled. Meshing gears 25 and 26 on the shafts 23 and 24respectively, are arranged within the compartment 22 and the loop taker20 is secured as by a setscrew 27 to one of the shafts 23 above thesaddle while a sprocket wheel 28 is secured to the other shaft 24beneath the saddle.

For shiftably supporting and for selectively securing each of thesaddles 21 in any one of a range of positions longitudinally of thesewing machine bed in accordance with this invention, each of thesaddles is formed with parallel guide channels 30, one channel alongeach side of the saddle. As shown in FIGS. 2 and 3, the sewing machinebed is formed with spaced depending webs 31 and 32 at each side of thethroat plate. The webs 31 and 32 extend lengthwise of the bed and definesupporting blocks between which the loop taker saddles may be arranged.

Secured by fastening screws 33 to the webs 31 and 32 are elongate ways34 each extending longitudinally of the sewing machine bed andsubstantially parallel to each other and to the work-supporting surfaceof the sewing machine bed as defined, for instance, by the throat plate17. Each of the ways 34 is formed with a guide surface 35 which iscomplemental to the guide channels 30 formed in the loop taker saddlesand preferably as shown in FIG. 2 has a blunt angular shape.

The distance between the webs 31 and 32, and the dimensions of the ways34 of the channels 30 in the loop taker saddles are chosen so as toprovide a snug support for the loop taker saddles which nonetheless willaccommodate a free-sliding movement of the saddles along the wayslengthwise of the sewing machine bed. At least one of each pair of theways for each of the saddles is formed with a recess 36 on the sideopposite the guide surface 35 and between fastening screws 33 so thatthe ways which are so recessed will have an unsupported central portionbetween the fastening screws. The web 31 is formed with a threadedopening which accommodates a crew 37 disposed to abut the way along therecess 36. A lock nut 38 is provided on the screw 37. By tightening thescrew 37 the recessed way may be deflected so as to lock the hook saddlein a selected position along the ways. While each of the ways 34 may beformed with a recess 36 and provided with an adjusting screw 37, it hasbeen found adequate to provide for deflection of only one of each set ofthe ways for each saddle in order to securely clamp the saddles in placeon the bed.

As shown in FIGS. 1 and 3, a main drive shaft 40 is journaled in the bedbeneath the standard 12 and provided with a pulley 41 by which thesewing machine. may be powered from any suitable motor, powertransmitter, or the like. A suitable drive may be provided from the maindrive shaft 40 to reciprocate the needles 16 and a timing belt 42 isillustrated in FIGS. 1 and 4 meshing with a sprocket 43 on the maindrive shaft 40 for this purpose. The main shaft 40 may also have fastthereon rotary actuators 44 and 45 for imparting movement to awork-feeding mechanism. As shown in FIG. 4, such a workfeeding mechanismmay include a feed bar 46 of a drop feed mechanism in which the rotaryactuator 44 takes the form of a feed eccentric for imparting feedadvance and return movements by way of a feed advance rock shaft 47journaled in the bed, and the rotary actuator 45 takes the form of agear for imparting movement to a feed lift driving shaft 48 journaled inthe bed. Any conventional work feeding mechanism, however, may beemployed.

For driving the loop takers 20, the main shaft 40 extends into a gearcompartment 50 in the bed wherein a bevel gear 51 is secured thereto.Meshing with the bevel gear 51 is a bevel gear 52 which is fast on astud shaft 53 journaled vertically in the bed compartment 50. Beneaththe gear 52 and below the compartment 50 a sprocket wheel 57 is carriedon the stud shaft 53.

The driven sprockets 28 and 28 for each of the loop takers are drivensynchronously from the drive sprocket 57 by a single timing belt 70. Thetiming belt 70 is directed to the driven sprockets 28 and 28 by a pairof idler rollers 71 and 72, the idler roller 72 being carried by abracket 75 which is secured by screws 76 to the machine frame while theidler roller 71 is carried by a bracket 80 secured by screws 81 to theloop taker saddle 21 The arrangement of timing belt 70, as illustratedin the accompanying drawings, provides for a shift of the loop takersaddle positions equidistant from a medial plane X-X between the needles16 without the necessity for disturbing the loop taker drive.Furthermore, this belt drive provides for simultaneously reestablishingtimed relations of both loop takers with their respective needles aftera position adjustment by adjustment of one connection in the drive trainsuch as the driving sprocket 57 relatively to the shaft 53. A copendingU.S. Pat. application Ser. No. 43,061, filed June 3, i970, ReinholdPapajewski, having a common assignee may be referred to for adescription in greater detail of this loop taker drive mechanism.

The operation of the present loop taker saddle support will be apparentfrom the following description of the steps involved in adjusting theloop taker saddles 21 of FIGS. 1 and 3 to accommodate a greater needlespacing. Assuming that the needle clamp 15 and throat plate have beenchanged, the clamp screw 37' as first loosened so that the recessed way34 will no longer be deflected. The loop taker saddle 21' therefore willbe freed for shift along the ways 34. Preferably, the loop taker saddle21 will be shifted into the new position using a gauge block to obtainan accurate setting. Since the clamp screw 37' does not engage the guidesurface 35' of the way 34, the way will not be scored or otherwisemarred by a previous clamping and even the smallest adjustment ofposition can be effected. When in desired new position, the loop takersaddle 21' is clamped in place by tightening the screw 37. The belt 70will have been loosened by the shift of the loop taker saddle 21' to theright as viewed in FIGS. 1 and 3, however, the loop taker saddle 21" isthen shifted a like amount to the left by the same process whichtightens the belt to the original state of tension. As explained indetail in the above referred to copending U.S. Pat. application, theloop takers, after being adjusted into new positions, may simultaneouslybe retimed relatively to the needles by adjusting the driving sprocket57 relatively to the shaft 53 on which it is carried.

Having set forth the nature of this invention, what is claimed hereinis:

1. Mechanism for supporting and clamping a loop taker saddle in theframe of a sewing machine comprising a pair of elongate ways, means forsecuring said ways in spaced substantially parallel relation in saidsewing machine frame, said loop taker saddle being formed with spacedchannels each embracing one of said ways slidably to support said saddlein said sewing machine frame, and means carried by said sewing machineframe for deflecting at least a portion of one of said ways toward thespace between said ways to clamp the loop taker saddle in selectedposition between said ways.

2. Mechanism for supporting and clamping a loop taker saddlein the frameof a sewing machine as set forth in claim 1 in which said ways compriseelongate bars formed at one side with a saddle channel engaging surfacewhich is substantially uniform in cross-sectional configuration alongthe entire length of said ways, in which at least one of said ways isformed along the side opposite said saddle channel engaging surface witha recess extending along a portion of the length of said way anddisposed in spaced relation to said sewing machine frame when said wayis secured thereto, and in which said deflecting means comprises anadjusting screw threaded into said sewing machine frame and impingingupon said recessed portion of said at least one way.

1. Mechanism for supporting and clamping a loop taker saddle in theframe of a sewing machine comprising a pair of elongate ways, means forsecuring said ways in spaced substantially parallel relation in saidsewing machine frame, said loop taker saddle being formed with spacedchannels each embracing one of said ways slidably to support said saddlein said sewing machine frame, and means carried by said sewing machineframe for deflecting at least a portion of one of said ways toward thespace between said ways to clamp the loop taker saddle in selectedposition between said ways.
 2. Mechanism for supporting and clamping aloop taker saddle in the frame of a sewing machine as set forth in claim1 in which said ways comprise elongate bars formed at one side with asaddle channel engaging surface which is substantially uniform incross-sectional configuration along the entire length of said ways, inwhich at least one of said ways is formed along the side opposite saidsaddle channel engaging surface with a recess extending along a portionof the length of said way and disposed in spaced relation to said sewingmachine frame when said way is secured thereto, and in which saiddeflecting means comprises an adjusting screw threaded into said sewingmachine frame and impinging upon said recessed portion of said at leastone way.